Yarn feeders of flat knitting machine

ABSTRACT

Yarn feeders are arranged such that feeder case portions are slidably engaged with a knitting yarn guide rail disposed to the upper portion of needle beds and can be selectively brought by bringing means, each of feeder cases is provided with a switching mechanism for switching a yarn feeding port to a feeding position and a waiting position and swinging it thereat, the switching mechanism is operated in a time during which a yarn feeder selected by the bringing means is brought from a stop state in order to feed yarn, the yarn feeding port is switched from the waiting position to the feeding position as well as a swinging direction of the yarn feeding port to the waiting position after it feeds yarn is set and the yarn feeding port can be switched from the feeding position to the waiting position in association with the selection cancel operation of the bringing means after it feeds the yarn.

TECHNICAL FIELD

[0001] The present invention relates to yarn feeders for a flat knitting machine, and more particularly to yarn feeders used to knit an intersia pattern.

BACKGROUND ARTS

[0002] A fabric having an intersia pattern can be formed by knitting the fabric with different yarns by switching several yarn feeders when one course is knitted without separating the fabric.

[0003] When the fabric having the intarsia pattern is knitted, as shown in FIG. 11, plural yarn feeders 12 a and 12 b are slidably disposed on a knitting yarn guide rail, the yarn feeder 12 a feed yarn to a first knitting region A, the yarn feeder 12 b feeds yarn to a second knitting region B, respectively, and the yarn feeder 12 a is replaced with the yarn feeder 12 b at respective yarn changing point. However, when the yarn feeder 12 a has fed yarn to the leftmost knitting needle of the knitting needles for knitting the knitting region A from a right side, the yarn feeder 12 a already passed through a point P1 and is positioned left.

[0004] Accordingly, when the yarn feeder 12 a is left at the position, a trouble occurs in that the knitting yarn extending in an obliquely lower right direction from the yarn feeder 12 a being left is erroneously fed to a knitting needle for knitting the next knitting region B.

[0005] To eliminate the trouble, a yarn feeder disclosed in Japanese Examined Patent Publication No. 61-51061 has been proposed.

[0006] In the yarn feeder of the above proposal, of the yarn feeders stopped on a knitting yarn guide rail by a brake unit, the yarn feeding port of a yarn feeder selected by a bringing means is first moved from a waiting position to a feeding position approaching knitting needles by sliding the bringing means, and then a braking force is released.

[0007] When the bringing means subsequently slides, the yarn feeder is brought thereby and feeds yarn to a predetermined knitting needle so that a predetermined region is knitted with it. Then, the yarn feeder is released from the bringing means and stopped by the brake unit.

[0008] When the yarn feeder further slides in the state that the yarn feeder is stopped by the brake unit, the yarn feeding port of the yarn feeder is switched from the feeding position to a waiting position that is moved inward of a knitted region knitted from the feeding position to prevent a trouble that a knitting needle in an adjacent knitting region is erroneously fed with yarn.

[0009] In the yarn feeder of the above proposal, however, a series of operations for switching the yarn feeding port of the yarn feeder from the waiting position to the feeding position, releasing a braking force, bringing the yarn feeder, and switching the yarn feeding port of the yarn feeder from the feeding position to the waiting position inward of a knitted fabric region knitted from the feeding position is executed while the yarn feeder travels from a time before it is brought to a time after it is brought. Accordingly, the sliding distance of the bringing means, which is required to execute the above operations, is increased, and hence the size of the yarn feeder is increased at the portion thereof operated by the bringing means. The problem of an increase in size of the yarn feeder also occurs in the yarn feeder disclosed in, for example, Japanese Examined Patent Application Publication No. 3-23662 and the like likewise.

[0010] When the size of the yarn feeder is increased, the weight thereof is increased, and a shock, which is generated when, for example, the bringing means brings the yarn feeder at a high speed, is increased, which requires to reinforce an apparatus in its entirety.

[0011] An object of the present invention, which was proposed in view of the above problems, is to provide yarn feeders for a flat knitting machine capable of switching a yarn feeding port from a feeding position to a waiting position in a short traveling distance of a bringing means without increasing the size of a portion selected and brought by the bringing means.

DISCLOSURE OF INVENTION

[0012] To achieve the above object, yarn feeders for a flat sewing machine according to the present invention are characterized by being arranged such that feeder case portions are slidably engaged with a knitting yarn guide rail disposed to the upper portion of needle beds and can be selectively brought by bringing means, each of feeder cases is provided with a switching mechanism for switching a yarn feeding port to a feeding position and a waiting position and swinging it thereat, the switching mechanism is operated in a time during which a yarn feeder selected by the bringing means is brought from a stop state in order to feed yarn, the yarn feeding port is switched from the waiting position to the feeding position as well as a swinging direction of the yarn feeding port to the waiting position after it feeds yarn is set and the yarn feeding port can be switched from the feeding position to the waiting position in association with the selection cancel operation of the bringing means after it feeds the yarn.

[0013] Next, yarn feeders for a flat knitting machine according to the present invention are characterized by being arranged such that that feeder rods are swingably and upward/downward movably pivoted by feeder cases at the intermediate portions thereof, yarn feeding ports are formed at the lower ends of the feeder rods, swingably operating portions are formed to the intermediate portions of the feeder rods, push-down operation portions for moving yarn feeder portions downward to a feeding position against upward urging force are formed at the upper ends of the feeder rods, setting units for setting the direction in which the swingably operating portions are moved upward and returned are provided, and switching mechanisms are arranged such that when the feeder rods are moved downward to position the yarn feeding ports at a feeding position, the upward-moving and returning direction of the swingably operating portions are switched by the setting units.

[0014] Further, one of the features of the yarn feeders for a flat knitting machine according to the present invention resides in that the waiting positions of the yarn feeding ports are set on upper sides of the yarn feeding positions in the sliding path of the bringing means along which the bringing means slides for feeding yarn, and the feeding positions are set at positions nearer to the knitting needles than the waiting positions of yarn feeding ports.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a side elevational view of a flat knitting machine having a yarn feeding apparatus including yarn feeders of the present invention.

[0016]FIG. 2 is an enlarged view of a yarn feeding portion of the present invention.

[0017]FIG. 3 is a view explaining the mechanism of the yarn feeder portion of the present invention.

[0018]FIG. 4 is an exploded perspective view of the yarn feeder portion of the present invention.

[0019]FIG. 5 is a view explaining an operation of a selection lever in the yarn feeder of the present invention.

[0020]FIG. 6 is a view explaining an operation of the selection lever in the yarn feeder of the present invention.

[0021]FIG. 7 is a view explaining an operation of the selection lever in the yarn feeder of the present invention.

[0022]FIG. 8 is a view explaining an operation of the selection lever in the yarn feeder of the present invention.

[0023]FIG. 9 is a front elevational view showing a modification of the selection lever in the yarn feeder of the present invention.

[0024]FIG. 10 is a front elevational view showing a modification of a push-down mechanism in the yarn feeder of the present invention.

[0025]FIG. 11 is a view explaining a knitting course in conventional knitting of an intersia pattern.

BEST MODE FOR CARRYING OUT THE INVENTION

[0026] An embodiment of a yarn feeder of a flat knitting machine of the present invention will be explained below based on the drawings.

[0027]FIG. 1 is a side elevational view of the flat knitting machine having a yarn feeding apparatus including yarn feeders of the present invention, wherein reference numeral 1 denotes a flat knitting machine in its entirety, and 2 denotes the yarn feeding apparatus.

[0028] The flat knitting machine 1 has a pair of needle beds 3 disposed on a frame 4 in a fan shape with the extreme ends thereof confronting each other, and each needle bed 3 has plural knitting needles 5 disposed thereon in parallel with each other so that they are movable back and forth.

[0029] A carriage 6 is disposed on the upper surface of each needle bed 3 so that it can be caused to reciprocatingly travel by a belt drive means (not shown), and the knitting needles 5 are advanced and retreated by a knitting cam 7 attached to the carriages 6.

[0030] A gate arm 8 is disposed to the carriages 6 so as to stride over the front and back needle beds 3 and integrally coupled with the carriages 6. Bringing means 10, which bring the yarn feeders 9, and push-down means 13, which push down the weft yarn ports 12 of the yarn feeders 9 to positions near to the extreme end of the knitting needles 5, 5, are mounted on the gate arm 8.

[0031] Four knitting yarn guide rails 11 are disposed on the upper portion of the needle beds 3 along the longitudinal direction thereof in a fan shape in the front and back direction of the needle beds 3 about the vicinity of the extreme ends of the knitting needles 5 disposed in parallel with each other on the needle beds 3.

[0032] The bringing means 10 are arranged approximately similarly to that disclosed in Japanese Patent No. 3044370.

[0033] That is, each bringing means 10 includes transmission rods 15 for transmitting the movement of the output shafts of solenoids, which are projected and retracted in response to a signal output from a controller (not shown), to bringing pins 14 as shown in FIG. 2. The bringing pins 14 are urged downward by springs 16 so that they bring the yarn feeders 9 by being engaged with engaging portions 19 formed to a pair of right and left swinging pieces 18 disposed to the feeder cases 17 of the yarn feeders 9 at portions near to the centers of the upper ends thereof (refer to FIG. 3).

[0034] Each yarn feeder 9 include the feeder case 17 slidably supported by a knitting yarn guide rail 11, a feeder rod 20 having a yarn feeding port 12 at the lower end thereof, and a feeder rod guide 21 for guiding the feeder rod 20 upward and down ward, the feeder rod 20 and the feeder rod guide 21 being formed by hanging down from the feeder case 17. The feeder rod guide 21 is swingably pivoted by the feeder case 17 at a pivot portion located near to an upper portion of it.

[0035] The feeder rod 20 is formed of a slender sheet-shaped lower plate 22 whose right and left side edge portions are supported by the feeder rod guide 21 so that it is slidably moved upward and downward, an intermediate plate 23 whose lower end portion is coupled with upper end portion the lower plate 22, and an upper plate 25 whose lower end portion is coupled with upper end portion of the intermediate plate 23 through a push-down roller 24 projecting from the upper back surface of the intermediate plate 23 and being engaged with a lateral slot 26 formed at the lower end portion thereof.

[0036] Coil springs 27 are mounted in an intermediate portion of the upper plate 25 between it and the spring receiving portions 28 of the feeder case 17 in order to urge the yarn feeding port 12 upward through the intermediate plate 23 and the lower plate 22.

[0037] Further, the switching roller 30 of a switching mechanism 29, which switches the attitude of the yarn feeding port 12, projects from the front surface of the intermediate plate 23 at the upper end portion thereof.

[0038] The switching mechanism 29 includes the switching roller 30, a regulation hole 31 formed through the feeder case 17 for regulating the swing motion of the switching roller 30, and a selection lever 32 disposed on the back surface side of the regulation hole 31.

[0039] As shown in FIGS. 3 and 4, the regulation hole 31 is formed in an approximately trifoliate shape having spaces, with which the regulation hole 30 is engaged, at upper, right, and left portions thereof.

[0040] The selection lever 32, which sets the upward moving direction of the switching roller 30 confronting the regulation hole 31, is formed in an approximately T-shape with its upper end portion 32 a formed in a gentle V-shape. The selection lever 32 is pivoted by the feeder case 17 at a pivot portion 32 b at a center as well as the lower portion thereof, which hangs down from the central portion of the upper end portion 32 a is formed in an arrow shape having inclining surfaces 33 and 34 on the right and left sides thereof for directing the upward moving direction of the switching roller 30.

[0041] Further, a holding mean 36, which holds the two switching attitudes of the selection lever 32, is disposed at an upper portion of an arrow-shaped portion 35 composed of the two inclining surfaces 33 and 34.

[0042] The holding means 36 is arranged such that beard-shaped elastic portions 37 are extended right and left from an upper portion of the arrow-shaped portion 35, and wrapping portions 38 and 39 are formed by curving the portions near to the extreme ends of the elastic portions as well as engaging projections 40 and 41 are formed on the back surface of the feeder case 17 so that they are engaged with any one of the wrapping portions 38 and 39 when the selection lever 32 is swung right or left.

[0043] The push-down means 13 for pushing down the feeder rod 20 is composed of a coupling plate 42 whose one end is coupled with the bringing pin 14 at intermediate height position thereof and a cam plate 43 whose upper end portion is coupled with the other end of the coupling plate 42. In the push-down means 13 arranged as described above, the cam plate 43 is swung back and forth about a swing pivot pin 44 in association with the up/down movement of the bringing pin 14.

[0044] As shown in FIG. 3, the cam plate 43 has a lower side portion formed flat and both ends formed in an inclining state, and the bringing pin 14 is disposed on the knitting yarn guide rail 11 side at the central position of the flat lower side portion.

[0045] Note that reference numeral 50 in FIG. 4 denotes a brake unit composed of a magnet attracted to the knitting yarn guide rail. Since the yarn feeder 9 is reduced in size and weight, the yarn feeder 9 can be stopped at an accurate position even by the light sliding friction generated by the attracting force of the magnet because. Accordingly, there does not arise such a problem caused in a conventional yarn feeder that when a yarn feeder being brought is to be stopped, it cannot be stopped at a desired position because the stop position of it is made unstable by the large inertia force thereof, and it is not necessary to provide a special brake unit for stopping the yarn feeder at the desired position by overcoming a large amount of inertia force of it.

[0046] Next, the operation of the yarn feeding apparatus when a fabric is knitted will be described.

[0047] When the carriages are is caused to travel on the needle beds 3, for example, from right to left (direction shown by an arrow A in FIGS. 3 and 5) by the belt drive means in response to a signal from the controller, the knitting needles 5 disposed in parallel with other on the needle beds 3 are advanced and retreated by the knitting cams 7.

[0048] When the carriages 6 travel, in a portion where no knitting is executed, a solenoid is actuated in response to an output signal for knitting a pattern so that the output shaft of the solenoid is projected downward, thereby the bringing pin 14 of a bringing means 10 is moved upward against the tension of a spring 16 through a transmission rod 15.

[0049] As the bringing pin 14 is moved upward, the cam plate 43 of a push-down means 13 is lifted up about a swing pivot pin 44 (refer to the cam plate 43 on the right side in FIG. 2).

[0050] Then, at the portion where knitting is executed, a solenoid is actuated in response to a signal output from the controller at a position in front of the position where a carriage 6 confronts a predetermined yarn feeder 9 for supplying yarn to knitting needles 5, and when the output shaft of the solenoid is retreated upward, a bringing pin 14 moved upward heretofore is pushed downward by the tension of a spring 16. In association with the pushed-down operation of the bringing pin 14, the cam plate 43 of a push-down means 13 is swung toward the yarn feeder 9 side about a swing pivot pin 44 through a coupling plate 42 (refer to the cam plate 43 on the left side of FIG. 2).

[0051] When the carriage 6 slides and the cam plate 43 pushes down the upper end portion 25 b of an upper plate 25 against the urging force of an coil spring 27, a switching roller 30 confronting a regulation hole 31 is placed in a state as shown in FIG. 6 in such a manner that it is guided and lowered to the central lower portion of the regulation hole 31 from the state shown in FIG. 5.

[0052] As the switching roller 30 is guided and lowered to the central lower portion of the regulation hole 31, the feeder rod guide 21 stands upright at the central portion of a feeder case 17 while projecting the yarn feeding port 12 of the feeder rod 20 downward from the lower end of the feeder rod guide 21, and the yarn feeding port 12 is located at a yarn feed position near to the knitting needles 5 on a needle bed 3.

[0053] When the carriages 6 further travels leftward and the bringing pin 14 presses the projecting upper end portion 32 a on a lower part (left side) of a selection lever 32, the selection lever 32 is swung counterclockwise about a pivot portion 32 b acting as the center of rotation as shown in FIG. 7. The attitude of the selection lever 32 is held by that the left wrapping portion 38, which forms a holding means 36, of the elastic portion 37 of the selection lever 32 is disengaged from the engaging a projection 40 and that the right wrapping portion 39 is engaged with an engaging projection 41.

[0054] Thereafter, when the bringing pin 14 is abutted against the engaging portion 19 of a swinging piece 18 located downstream of the advancing direction of the selection lever 32, the yarn feeder 9 is brought by the carriage 6, and yarn is fed to the knitting needles 5 from the yarn feeding port 12 of the yarn feeder 9, thereby a knitting portion is knitted with the yarn fed from the yarn feeder 9.

[0055] When the knitting potion has been knitted, the solenoid is energized in response to a signal output from the controller, the output shaft of the solenoid is projected downward, and the bringing pin 14 moved downward heretofore is pushed upward against the tension of the spring 16. As the bringing pin 14 is moved upward, the cam plate 43 of the push-down means 13 is swung by being lifted up about the swing pivot pin 44.

[0056] When the bringing pin 14 is moved upward and disengaged from the engaging portion 19 of the swinging piece 18 located downward of the advancing direction of the carriage 6, the yarn feeder 9 is released. In addition, since the cam plate 43 is lifted up and swung, the feeder rod 20 pushed down heretofore is pushed upward by the coil spring 27 to a position where the feeder port 12 at the lower end thereof does not interfere with the yarn feeding port 12 of other yarn feeder 9, knitting needles 5, sinkers and the like.

[0057] When the feeder rod 20 is pushed upward by the coil spring 27, the selection lever 32 is already switched in a counterclockwise direction. Accordingly, when the switching roller 30 is moved upward, it is moved upwardly left by being guided by the left inclining surface 33 of the selection lever 32 as shown in FIG. 8. As a result, the yarn feeding port 12 is moved upward in a state that it is swung right together with the feeder rod guide 21.

[0058] Next, when the carriage 6 arrives at a predetermined position where knitting yarn is changed, a solenoid is actuated to other yarn feeder 9 to be changed in response to a signal output from the controller similarly to the operation described above, the output shaft of the solenoid is retreated upward, the bringing pin 14 moved upward heretofore is pushed downward by the tension of the spring 27 as well as the cam plate 43 of the push-down means 13 is swung to the yarn feeder 9 side about the swing pivot pin 44.

[0059] After the bringing pin 14 is moved downward, the fabric is knitted with knitting yarn fed from the yarn feeding port 12 of a yarn feeder 9 selected by the same procedure as that described above.

[0060] It should be note that although the above embodiment explains the case that the carriages 6 is caused to travel on the needle beds 3 from right to left by the belt drive means, knitting can be executed similarly when the carriages 6 travels thereon from left to right.

[0061] Further, in the above embodiment, the holding means 36 is arranged such that the beard-shaped elastic portions 37 extend from the upper portion of the arrow-shaped portion 35 right and left, the wrapping portions 38 and 39 are formed by curving the portions of the elastic portions 37 near to the extreme ends thereof as well as the engaging projections 40 and 41, which are engaged with any of the wrapping portions 38 and 39 when the selection lever 32 is swung right or left, are disposed on the back surface of the feeder case 17. However, the holding means 36 is not limited to the above arrangement and may be arranged, for example, such that plural recesses or holes 45 are formed at a portion of the selection lever 32 as shown in FIG. 9 and a ball or a pin (not shown), which is engaged with the recesses or the holes 45, is urged on an engagement side by a spring.

[0062] Further, in the above embodiment, the push-down means 13 is composed of the coupling plate 42 whose one end is coupled with the bringing pin 14 at the intermediate height position thereof and the cam plate 43 whose upper end portion is coupled with the other end portion of the coupling plate 42, and the cam plate 43 is swung back and forth about the swing pivot pins 44 in association with the upward/downward movement of the bringing pins 14. However, the push-down means 13 may be altered as shown in, for example, FIG. 10.

[0063] That is, a receiving piece 46, which is formed by upsetting the cam plate 43 of the above embodiment, is disposed to the upper end portion of the feeder rod as well as and the receiving piece is pushed downward and the selection lever 32 is switched by traveling the bringing pin 14.

INDUSTRIAL APPLICABILITY

[0064] As described above, the yarn feeders for the flat knitting machine according to the present invention have the feeder case portions, which are slidably engaged with the knitting yarn guide rail disposed to the upper portion of the needle beds and can be selectively brought by bringing means, and the feeder cases each of which is provided with the switching mechanism for switching the yarn feeding port to a feeding position and waiting positions, wherein the switching mechanism has the yarn feeding port and the two waiting positions, i.e. a first waiting position and a second waiting position located across the yarn feeding port, the switching mechanism is operated in a time during which a yarn feeder selected by the bringing means is brought from a stop state in order to feed the yarn, the yarn feeding port is switched from the first waiting position to the yarn feeding position, the swinging direction, in which the yarn feeding port is swung to the second waiting position after it feeds the yarn, is set, and the yarn feeding port can be switched from the feeding position to the second waiting position in association with the selection cancel operation of the bringing means after it feeds the yarn.

[0065] With the above arrangement, the sliding distance of the bringing means, which is required to execute a series of operations for switching the yarn feeding port of the yarn feeder from the waiting position to the feeding position, bringing the yarn feeder, and switching the yarn feeder ports of the yarn feeder from the feeding position to the waiting position inward of a knitted fabric region knitted from the feeding position, can be shortened, and hence an increase in size of the portions of the yarn feeders actuated by the bringing means can be prevented.

[0066] Since the increase in size of the yarn feeders can be prevented, an increase in weight of the yarn feeders can be also prevented. As a result, there can be also obtained advantages that even if the bringing means brings the yarn feeders at a high speed, a shock caused in this process can be reduced, thereby the apparatus need not be reinforced in its entirety and the durability of the apparatus can be improved. 

1. (Amended) Yarn feeders for a flat knitting machine in which feeder case portions are slidably engaged with a knitting yarn guide rail disposed to the upper portion of needle beds and can be selectively brought by bringing means, each of feeder cases is provided with a yarn feeding position and two waiting positions, i.e. a first waiting position and a second waiting position across the yarn feeding position for a yarn feeding port and with a switching mechanism for switching a yarn feeding port to the feeding position and the first and second waiting positions and swinging it thereat, characterized in that, of the two waiting positions of the yarn feeding port, the waiting position, which is located on the upper side than the feeding position of the sliding path of the bringing means along which the bringing means slides for feeding yarn, is set as the second waiting position, the other waiting position located across the feeding position is set as the first waiting position, the switching mechanism switches the yarn feeding port from the first waiting position to the feeding position in a time during which a yarn feeder selected by the bringing means starts to be brought from a stop state as well as sets a swinging direction such that the yarn feeding port is swung from the feeding position to the second waiting position after it feeds the yarn and can switch the yarn feeding port from the feeding position to the second waiting position in association with the selection cancel operation of the yarn feeder executed by the bringing means after the yarn is fed.
 2. Yarn feeders for a flat knitting machine according to claim 1, characterized in that feeder rods are swingably and upward/downward movably pivoted by feeder cases at the intermediate portions thereof, yarn feeding ports are formed at the lower ends of the feeder rods, swingably operating portions are formed to the intermediate portions of the feeder rods, push-down operation portions for moving yarn feeder portions downward to a feeding position against upward urging force are formed at the upper ends of the feeder rods, setting units for setting the direction in which the swingably operating portions are moved upward and returned are provided, and switching mechanisms are arranged such that when the feeder rods are moved downward to position the yarn feeding ports at a feeding position, the upward-moving and returning direction of the swingably operating portions are switched by the setting units.
 3. (Deleted) 